package day20171102;

/**
 * Created by Administrator on 2017-11-2.
 */
public class Test {

    public static void main(String[] args) {

        // 三科成绩：数学，英语，Java
        double[] threeScores = new double[3];
        threeScores[0]  = 98.8;
        threeScores[1] = 98.9;
        threeScores[2] = 99.9;


        // 基本数据类型

        // 复合数据类型
        Phone[] pheones = new Phone[10];




        // String
        String hello = "Hello, World!";
        hello.charAt(0);
        hello.indexOf("World");
        String[] result =  hello.split(",");


//        System.out.println(hello.toLowerCase());
//        System.out.println(hello.toUpperCase());

        System.out.println(hello);
        System.out.println(hello.trim());

        System.out.println(hello.substring(2,5));

        StringBuffer stringBuffer = new StringBuffer();
        // append 追加
        stringBuffer.append("hello");
        stringBuffer.append(",");
        stringBuffer.append("world!");

        System.out.println(stringBuffer.toString());


    }
}
